Information security in multiservice communication networks is analyzed using network attack detection methods. In this paper, various network attack detection methods are selected and investigated. In addition, a structural diagram network anomaly detection in multiservice communication network is proposed. The purpose of the work is to study and analyze the indicators of information security in multiservice communication networks using network attack detection methods. This work focuses on the consideration of a generalized classification scheme of network attack detection methods, the presentation of the essence of each of the considered methods and their comparative analysis. Based on the study of entropy analysis methods, analytical expressions were obtained that allow us to evaluate the informative characteristics of the source of traffic messages.